1. Field of the Invention
This invention relates to a conveyor system. More specifically, it relates to a conveyor system of a copier for moving documents onto the glass exposure platen or copies through a toner transfer station.
2. Description of the Prior Art
Conveyor systems of the kind described above are known. For example, Xerox Disclosure Journal, Volume 5, 1980, No. 4, page 369, discloses a typical conveyor system in which an insulating rubber belt is trained about two electrically conductive rollers. This system is secured a short distance above the glass exposure platen of a copying machine. A document feeder is provided to feed a document between the belt and the exposure platen. The belt conveys the document over the exposure platen, and after exposure it removes the document from the platen.
Tribo-electric charging of the insulating belt over the conductive rollers induces a charge on the platen so that the document sticks to the platen. Static charge eliminators are disposed near the belt to reduce this induced charge. Xerox Disclosure Journal, Volume 2, 1977, No. 6, page 81 shows a pin-type, corona-generating static charge eliminator. Although these static charge eliminators reduce the charge on the belt, the reduction is generally indadequate to guarantee reliable transport of the document. Thus, there is a need to provide a conveyor system which obviates this disadvantage and sufficiently reduces the static charge to guarantee reliable transport of the document.
U.S. Pat. No. 4,172,905 relates to a method of transferring images from one surface to another without the use of an insulating belt. That patent specifically teaches that a high level of charge is built up on an insulated roller which is not grounded. European patent application No. 0,118,137 relates to a device for transferring image information which uses electrically conductive rollers. Finally, U.S. Pat. No. 2,897,425 is directed to an apparatus for producing electrostatic force between a semiconductor and a conducting object wherein the endless belt must be made from a conducting material, either magnetic or nonmagnetic.